DNA in bones
The most abundant remains of dinosaurs are their fossilized bones. Therefore, dinosaur bones are the most obvious place to look for dinosaur DNA. Bones haven't as good preservation properties as ice or amber. Nonetheless, DNA has been recovered from 300,000 years old unfrozen bone specimens. Multiple scientists have claimed to extract DNA from dinosaur bones. However, most scientists believe DNA can't last 65 million years in bones. The discovered DNA could be contamination. Jurassic Park media Films In the 2010s, after the discovery that soft tissue in dinosaur bones still contains ancient DNA, InGen started to collect DNA from fossils. Dr. Christopher Reddy called the soft tissues "goldmines of DNA". InGen could now supplement the DNA in Amber with the DNA from the fossils, instead of the DNA from frogs. As a result, InGen was approaching 100% genome accuracy in dozens of species.InGen Technologies Tomorrow, Today (HD) Other The concept of ancient DNA in dinosaur bones is mentioned in the novels. When Lewis Dodgson, a scientist from InGen's rival corporation, tries to convince the board that InGen has cloned dinosaurs, it is the sole source of dinosaur DNA Dodgson can think of.Michael Crichton (1990). . Chapter: Target Of Opportunity, page 68. In the video game Jurassic Park: Operation Genesis DNA can be extracted from dinosaur bones. They do not contains as much DNA as amber. However, the species of the DNA is know before the player has to spend money to extract the DNA. Ancient DNA from bones Tens of thousands of DNA base pairs were recently sequenced from 40,000-year-old skeletal remains of cave bears without using PCR, establishing that, in principle, large-scale genomic sequencing of fossilized remains is possible Noonan and team (2005). Genomic Sequencing of Plestiocene Cave Bears. Fragments of are extracted from 300,000 year old bones from Spain.Dabneya J., Knappb M., Glockea I., Gansaugea M-T., Weihmanna A., Nickela B., Valdioserad C., Garcíad N., Pääboa S., Juan-Luis Arsuagad J-L.,Matthias Meyera M. (2013). Complete mitochondrial genome sequence of a Middle Pleistocene cave bear reconstructed from ultrashort DNA fragments, PNAS. Of course, the remains used in these studies are orders of magnitude younger than anything from the dinosaur era, and the technique might not extend to those creatures. How long can DNA last The scientific community has accepted that proteins and soft tissue can survive tens of million years in unfrozen bones. How long DNA can last in unfrozen bones, however, is a matter of fierce scientific debate. Pruvost and his team (2007) reported that freshly excavated bones contain more DNA than specimens that have been stored in museum for years.Pruvost et al (2007). Freshly excavated fossil bones are best for amplification of ancient DNA, PNAS, volume 104 no. 3, pages 739-744. link Their article says: we demonstrate that freshly excavated and nontreated unwashed bones contain six times more DNA and yield twice as many authentic DNA sequences as bones treated with standard procedures. Finally, we compared the DNA content in the fossil bones of one animal, a 3,200 year-old aurochs, excavated in two separate seasons 57 years apart. Whereas the washed museum-stored fossil bones did not permit any DNA amplification, all recently excavated bones yielded authentic aurochs sequences. We established that during the 57 years when the aurochs bones were stored in a collection, at least as much amplifiable DNA was lost as during the previous 3,200 years of burial. under construction DNA from dinosaur bones In 1994, scientists claimed to have successfully extracted DNA from two Cretaceous bone fragments Woodward and team (1994). DNA sequence from Cretaceous period bone fragments. However, further studies by at least 5 different laboratories found that the supposed dinosaur DNA was merely contamination from modern human DNA Zischler and team (1995). Detecting dinosaur DNA. Similarly, in 1995, scientists in China reported finding DNA in a fossil dinosaur egg Li and team (1995). DNA isolation and sequence analysis of dinosaur DNA from Cretaceous dinosaur egg in Xixia Henan, China. However, further studies found that the DNA was actually from modern fungus Wang and team (1997). Reanalysis of Published DNA Sequence Amplified from Cretaceous Dinosaur Egg Fossil. In 1995, DNA was reported in osteocytes of the tyrannosaurid ''Tarbosaurus''Pawlicki (1995). Histochemical demonstration of DNA in osteocytes from dinosaur bones. However, the source of the DNA could not be verified. Schweitzer and her team analysed T. rex and Hadrosaur bones for DNA. The results (published in 2013) are shown in this figure. The top row shows bones cells of'' T. rex'', the second Brachylophosaurus, the last ostrich. The scientists used three techniques to stain the DNA: anti-DNA antibodies (1st column), propidium iodide (PI) (2nd column), DAPI (last column).Schweitzer and team (2012). Molecular analyses of dinosaur osteocytes support the presence of 3 endogenous molecules, Bone, Volume 52, Issue 1, Pages 414–423. It is unlikely that this DNA is of bacterial origin. Just like in ostrich cells, only the cores of the cells are stained. Another analysis identified histones near the DNA, bacteria don't have histones. References Category:Science of Jurassic Park